NUT

Table of Contents

1. Description

NUT is a low overhead generic container format. It stores audio, video, subtitle and user-defined streams in a simple, yet efficient, way.

It was created by a group of FFmpeg and MPlayer developers in 2003 and was finalized in 2008.

2. Container-specific codec tags

2.1 Generic raw YUVA formats

Since many exotic planar YUVA pixel formats are not considered by the AVI/QuickTime FourCC lists, the following scheme is adopted for representing them.

The first two bytes can contain the values: Y1 = only Y Y2 = Y+A Y3 = YUV Y4 = YUVA

The third byte represents the width and height chroma subsampling values for the UV planes, that is the amount to shift the luma width/height right to find the chroma width/height.

The fourth byte is the number of bits used (8, 16, ...).

If the order of bytes is inverted, that means that each component has to be read big-endian.

2.2 Raw Audio

<type> is S for signed integer, U for unsigned integer, F for IEEE float <interleaving> is D for default, as a historical artefact. <bits> is 8/16/24/32

PFD[32]   would for example be signed 32 bit little-endian IEEE float

2.3 Subtitles

2.4 Codecs